Benchmark 5000-6000 Operation & Maintenance Manual
SECTION 5
– TROUBLESHOOTING GUIDE
OMM-0118_B
•
GF-203
•
5/9/2019
Technical Support
•
(800) 526-0288
•
Mon-Fri, 8 am - 5 pm EST Page 70 of 148
TABLE 5-1: Boiler Troubleshooting Procedures
FAULT
INDICATION
PROBABLE CAUSES
CORRECTIVE ACTION
IGN SWTCH
OPEN
DURING
IGNITION
1.
Air/Fuel Valve not rotating to ignition position.
2.
Defective Ignition switch.
3.
Defective Power Supply Board or fuse.
4.
Defective IGST Board.
1.
Start the unit. The Air/Fuel Valve should rotate to the purge (open)
position, then back to ignition position (towards closed) during the
ignition cycle. If the valve does not rotate back to the ignition
position, check the Air/Fuel Valve calibration. If calibration is okay,
the problem may be in the Air/Fuel Valve or the C-More Controller.
Refer fault to qualified service personnel.
2.
If the Air/Fuel Valve does rotate to the ignition position, check the
ignition position switch for continuity between the N.O. and COM
terminals when in contact with the cam.
3.
Check DS1 & DS2 LEDs on Power Supply Board. If they are not
steady ON, replace Power Supply Board.
4.
Check “Heartbeat” LED DS1 and verify it is blinking ON & OFF
every second. If not, replace IGST Board.
INTERLOCK
OPEN
1.
Interlock jumper not installed or removed.
2.
Energy Management System does not have
unit enabled.
3.
Device proving switch hooked to interlocks is
not closed.
1.
Check for a jumper properly installed across the interlock terminals
in the I/O box.
2.
If there are two external wires on these terminals check any
Energy Management system to see if they have the units disabled
(a jumper may be temporarily installed to see if the interlock circuit
is functioning).
3.
Check that proving switch for any device hooked to the interlock
circuit is closing and that the device is operational.
LINE VOLTAGE
OUT OF PHASE
1.
Line and Neutral switched in AC Power Box.
2.
Incorrect power supply transformer wiring.
1.
Check hot and neutral in AC Power Box to ensure they are not
reversed.
2.
Check transformer wiring, in AC Power Box, against the power box
transformer wiring diagram to ensure it is wired correctly.
GAS
PRESSURE
FAULT
(Due to Low Gas
Pressure)
1.
Incorrect supply gas pressure.
2.
Defective Low Gas Pressure switch.
1.
Measure NATURAL GAS pressure upstream of the SSOV
Actuator(s) with the unit firing. The minimum is
14” W.C.
(3.5 kPa)
,
although the BMK 6000
can operate with derating at
11” W.C. (2.7
kPa)
and the
BMK 5000 can operate with derating at
10” W.C.
(2.5 kPa)
.
2.
Measure NATURAL GAS pressure at the Low Gas Pressure
switch. If it is
greater than 10” W.C. (2.5 Pa)
, measure continuity
across the switch and replace if necessary.
